Suppressor condenser integral with brush holder



Nov. 23, 1943.

C; B. MIRICK EI'AL SUPPRESSOR CONDENSER INTEGRAL WITH BRUSH HOLDERS Filed June 26, 1941 m .me 8% y mw M um m z u n V: B I IH- .l 2 o- 0 UNITED STATES PATENT OFFICE surrmzssoa CONDENSER INTEGRAL WITH BRUSH nommn Carlos B. Mirick and Albert P. Green, Washington, D. 0.

Application June 26, 1941, Serial No. 399,857

3 Claims. (01. 171-324) Granted under the act orMarch 3, 1883, as amended'April 30, 1928; 370 0. G. 757) This invention relates to electrical apparatus the following detailed description when conand more particularly to an arrangement for efsidered with the attached drawing which i11us electrical machines. ing is designed for purposes of lllustrationonly It has been found that during operation of and not as a definition of the limits of the inelectrical machines of the type wherein relative vention, reference being had for the latter pur-. movement occurs during operation thereof be- D to the ppended Claims. tween electrically conducting members, such as n the r w n wherein similar reference charthe commutator and brushes of the ordinary elec- '1 a ters denote Simi p s throughout e vtric motor or of a machine for generating electric eral views: energy, that sparks occur at the point of contact 1 is a diag ammatic view, partly in section, between such members and that the formation of of a structure embodying the p inc p es of t such sparks originate high frequency oscillations, p esent inv ntion, and v which, in turn, cause electrical interference in i 2 is a dia am a i iew.sh w svan0th r radio reception. Various arrangements have view of the structure disclosed in Fig. 1. heretofore been proposed for eliminating electrical Referring more particularly to the drawing, an interference in radio reception caused in the above arrangement constructed according to the prinm n Althou h thes prior arrangements ciples of the present invention is disclosed therein utilized electric interference eliminating elements, 2 Which includes a shaft I0 of an electric motor such as condensers, they do not operate effectively generator or any other electrical machine of this to eliminate all electrical interference which oct pe. not S ow A commut or L, constructed curs upon operation of electrical machines of the in t usual anner having D t y 0f 8'- foregoing type, nor do they provide an adequate merits l2 positioned about the periphery thereof, installation of the electrical interference eliminat- 5 is dly secured to the shaft I0 and is adapted ing elements whereby the latter may operate at to rotate therewith. A brush I3 is provided fOl t highest, possible effici ncy t suppress and forming an electrical connection between the bypass t high frequency ll t segments of the commutator and a terminal H of 1:; i therefore an object; of t present; jnvem the electrical machine through a wire I 5 in a tion to provide a novel arrangement for eliminat- Conventional mannerhe b ush I3 is mounted ing the foregoing disadvantages. for substantially free longitudinal movement in a Another object is to provide a novel arrangesupport member 16 and one end thereof is held in ment for effectively eliminating all electrical lI1- electrical contact with the periphery of the comterference occasioned by relative movement bemutatol y means of a Spring l7 bearing on the tween certain elements of various electrical ap- 0- other end A member at a d o O forming paratus, a part of the member I6, secures the brush l3 and still nothe bj t i t provide i an a the support therefor on a stationary portion of langement of th foregoing h ra t a novel the electrical machine, such as an insulated porstructure for utilizing electric interference elimition H3. The member 18 also forms a support for hating elements, such as condensers, in an effecthe terminal l4. tiv manna; As heretofore stated, the present invention pro- Still another object of the present invention is vides means for effectively eliminating all electo provideanovel arrangement in connection with t l n r r n n i ing of hi h frequency l -m machines having commutator a oscillations caused by relative movement between brushes for eifectively eliminating all electrical in electrically conducting elements of varinterference occasioned by relative movement below? electrical machines, and for installing and tween the commutator and the brushes electrically connecting electrical interference further object i to provide in a tructure of eliminating elements in Such a manner the the above type a novel arrangement for position- Same may p r t at maximum efficiency to sup- :lng electrical interference eliminating elements Press and bypass e h fr qu n y osci ations near th point where electrical interferences origwhereby such oscillations will not cause electrical inate whereby such elements are effectively utin e e n adio re eption. lized. for eliminating such electrical interference. Such means, as shown in the drawings, inoth objects and features of t present i cludes an electrical interference eliminating ele- Vention will appear more fully hereinafter from ment 20 Which m y ta e t e o m of a usual condenser having high and low potential connections thereof. The element 20 is secured to or constructed integral with the brush supporting member l6 so that the high potential connection of the condenser is in electrical contact with the supporting member. Such construction is provided since it has been found that condensers, when utilized as electrical interference eliminators, operate at maximum efficiency when mounted adjacent the junction where the high frequency'oscillations, or the source of electrical interference, originates. In order to further increase the efficiency of the condenser for suppressing and bypassing high frequency oscillations 9. positive electrical connection is provided between the high potential connection of the condenser and the brush i3, which connection comprises a wire 2i which may be substantially short since the condenser is positioned adjacent the brush. It is to be expressly understood, however, that the load through the brush I3 is carried by the connector i5, and not by means of the wire 2!. The low potential side of the condenser is electrically connected to an adiacent, non-insulated portion of the machine, such as portion 22 of the frame thereof, through a wire 23, to thus complete the electrical circuit.

The present invention thus provides a novel arrangement for effectively eliminating high frequency oscillations which occur upon sparking about the commutators of various electrical ma-' chines, which, in turn, cause electrical interference in radio reception. A novel arrangement for utilizing electrical interference eliminating elements is also disclosed by the present invention, wherein the elements are positioned adjacent the point or junction where the frequency oscillations originate whereby the electrical connectors required to complete the circuit may be very short to thus increase the efficiency of the elements for suppressing and bypassing frequency oscillations.

Although only one embodiment-of the invention has been shown and described in detail herein, it is to-be expressly understood that various changes and substitutions may be incorporated therein without departing from the spirit of the invention as well understood by those skilled in the art. Reference will, therefore, be had to the appended claims as a definition of the limits of the invention.

The invention described herein may be manufactured and/or used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed is:

1. In an electrical apparatus having a frame, a commutator mounted for rotation in said frame, a brush inelectrical contact with said commutator, a support forsaid brush, a condenser having high and low potential connections, means for positioning the condenser on said support whereby the latter is electrically connected to the high potential connection of said condenser, an electrical conductor connecting said high potential connection directly to said brush, means for electrically connecting the low potential connection of said condenser to the frame whereby the condenser eflectively'operates to bypass and suppress high frequency oscillations, and another electrical conductor connected to said brush for carrying the electrical load of the apparatus.

2. In an electrical machine having a rotatable member, a non-rotatable member in electrical contact with said rotatable member, a support for said non-rotatable member, electrical interference eliminating means positioned on said support, and a plurality of electrical conductors connected to said non-rotatable member, one of said conductors serving to electrically connect said electrical interference eliminating means and said non-rotatable member, and the others serving to carry the electrical load of the machine.

3. An electrical machine having a commutator and a brush in electrical contact with said commutator, a support for said brush, electrical interference eliminating means positioned on said support, and a. plurality of electrical conductors connected to said brush, one of said conductors serving to electrically connect said electrical interference eliminating means and said brush,

and another one of said conductors serving to carry the electrical load of said machine.

CARLOS B. MIRICK. ALBERT P. GREEN. 

